<!DOCTYPE html>
<html>
	<head>
		<meta charset="UTF-8">
		<style>
			.child {
				background-color: red;
			}
			
			.parent {
				opacity: 0.5;
			}
		</style>
	</head>
	<body>
		<div id="app">
			<my-input type="checkbox" class="parent"></my-input>
		</div>
		
	    <script src="https://unpkg.com/vue@next"></script>
		<script>
		    const app = Vue.createApp({});
			app.component('MyInput', {
	            template: '<input class="child" type="text">'
      		});
  		
			app.mount('#app');
		</script>
	</body>
</html>